Lubricant



Patented June 4, 1940 UNlTED STATES LUBRICANT Thomas J. Brown, Cohoes, N. Y. I

No Drawing.

6 Claims.

This invention relatesto lubricants and particularly to lubricating oils, gear. lubricants and greases employed for lubricating transmission gears, differential gears and other similar gear mechanisms requiring a lubricant having a low pour or channeling point. This application is a continuation in part of my application filed November 8, 1933, Serial No. 697,197.

At the present time, the two most .common 10 lubricants employed for lubricating transmission and difierential gears are gear lubricants and greases. Gear lubricants are straight mineral oils, which may be light or heavy, and while these have been found highlydesirable for use in'lubricating gears'it has been found impossible to use the heavy gear lubricants because of their high channelingpoint-whlch makes them unsuitable for low temperature operation. Consequently, it has been possible to use only light gear 50 lubricantsup' to this time, for. low temperature operation; and these oils are not suitable for high temperature operation, unless fillers are added to increase the consistency of the grease. Greases are-now largely used for gear lubrication and conslst of light'straight mineral oils .to which are added tallow, soap, animal fats, et cetera, to produce an artificial body or consistency. Inasmuch as the filler in the grease. produces merely the desired consistency for proper retention under 30 the given conditions, it is a fallacy. to believe that the consistency of the, grease is also .an indication of its lubricating or load-carrying ability. Therefore, the high quality of a lubricant depends solely upon the quality of the straight mineral oil 88 used, and consequently'it can be readily seen it is highly desirable to use straight mineral oils of a high viscosity without the addition of fillers, ii the channeling point ofsuch oils canbe, lowered to permit their usein low temperature. operation.

40 An object of the present invention resides in providing a depressant for lowering the pour or channeling point of straight mineral gear lubricants" which is readily miscible with'the lubricants and will remain admixed'therewith during the entire time of its use.

A further object of the invention resides in provldlng a pour or" channeling point depressant which may be admixed with greases containing straight mineral gear oils, whereby the channeling point of the grease will be lowered to permit a heavy grease to be used under both high and low temperature operating conditions.

A still further object of the invention resides in providing a depressant which when added to bright stocks and heavy gear lubricants permits other depressants such as Paraflow and "Santapour to be effective in further reduction of the pour point. do Other objects and advantages of the invention Application January 11 1939, Serial No. 250,420

The depressant may be used in treating any mineral. oil either of a paraffin, mixed, or asphalt base. The reaction of the'depressant on paraiii'n, mixed base oils, and asphalt-base gearlubricants is practically the same, whereas a larger percent of the depressant is necessary to obtain the same results with an asphalt-base motor oil. -The reaction of the depressant with greasescontaining a mineral oil is determinedbythe character of the base'of the mineral ,oil in the grease and the filler employed in compounding the grease. A grease containing an animal fat as a..filler will have its pour point reduced by adding thedepressant to the grease, but where the filler is-a soap, lead, or the like, the depressant has been found 'to break down the grease'sothat the filler no longer remains in suspension and for this reason it has been found unsatisfactory to use the depressant with greases other than those containing animal fats as a-filler. However, it is to be understood that the depressant when added to all kinds of greases will reduce'the channeling point'of the grease, but owing to the effect it has upon the filler ofgreases containing fillers other than animal fats it is foundto. be commercially unsuited for usewith such greases, While It will thus be seen that oneof'the primary advantages of my depressant is that it will permit straight heavy gear lubricants to be used as lubricants in the automotive field,-whereas-they have been heretofore unsuitable because of their high pour or channeling points,.-and .owing to thesuperior lubricating qualities of such" lubricants it is believed my invention will entirely dispense with the use of greases in the automotive field.

The depressant employed to lower the channeling point of straight mineral gear lubricants and greases is para-cymene, a hydrocarbon product which is readily miscible with mineral oils and has a distillation point of 175 C. The depressant may be mixed with the oil at room temperature by agitation, although the blending of the oil and depressant may be accelerated by first heating the oil to a temperature of about 160 F. to 180 F. and then adding the unheated paracymene to the heated oil. The exact reaction of para-cymene on the oil is not known, although tests show when used with oils of a paraflin base or containing paraffin, the paraflin is caused to separate out of the oil as a flocculent precipitate. The action of the para-cymene on asphaltbase oils containingv no parafiin is the same as a solvent, as it reduces all fats and greases and is an oil solvent. The viscosity of para-cymene is much less than the oil to which it is added, and naturally will act to thin the oil to a degree, but dilution is not its only reaction, as is shown by a test in which 5% of para-cymene added to a 300 Pale asphalt oil reduced the pour point of the oil only slightly, while the same percentage of para-cymene added to a paraffin-base oil that .was 'over eight times the viscosity of the Pale oil,

reduced the pour point of the paraflin-base oil many degrees greater.

Tests which I have conducted show the following results: Y

Treating a Pennsylvania Bright Stock straight mineral oil, 100% paraffin base, having a viscosity of 2400 100 and 160 210 showed the pour point of the oil to be as follows:

Untreated pour point plus 20 F. 2% of para-cymene pour point plus 20F. 5% of para-cymene pour point plus 10 F. 10% of para-cymene pour point plus 5 F.

A winter light gear lubricant number having a viscosity of 933 and 83 210 showed the pour point of the oil to be as follows:

Untreated pour point minus 5 F. 2% of para-cymene pour point minus 10 F. 5% of para-cymene pour point minus 20 F.

10% .of para-cymene pour point minus 35 F.

An extra heavy gear lubricant having a viscosity of 3885 100 and 191 210 showed the pour point of the oil to be as follows:

Untreated -4- pour point plus 50 F. 2% of para-cymene pour point plus 40 F. 5%Yof para-cymene pour point plus 20 F. 10% of para-cyrnene pour point plus zero cosity as above stated showed the pour point of the oil to be as follows:

Untreated pour point plus 50 F. 2% of para-cymene and.

5% Santapour pour point plus 12 F. 5% of para-cymene and 5% Santapour pour point plus 4 F. 10% of para-cymene and 5% Santapour pour point minus 12 F.

A Bright Stock oil of the same viscosity as 2,208,044 I g 4 above stated, treated in the same manner, showed the following results:

Untreated pour point plus 20 F. 2% of para-cymene 'pour point plus 20 F. 2% of para-cymene and 5% Santapour pour point plus zer 5% of para-cymene and 5% Santapour pour point minus 10 F. 10% of para-cymene and 5% Santapour pour point minus 20 F.

In tests I have conducted it has been found that the percentage of para-cymene will vary according to the type of oil'to be treated. The pour point of Pennsylvania and Mid-Continent Bright Stocks will be reduced by 2% or more of para-cymene mixed therewith. Gear lubricants of both the paraffin and asphalt-basetypes require the ad-' reduce the pour point of the oil to a greater deagree than a larger percent of the para-cymene used alone, but in treating all types of bright stocks and heavy gear lubricants para-cymene must be added ,in order to make Paraflow or Santapour effective. However, itis to be understood the pour point of thelubricant may be depressed by the use of para-cymene alone.

The invention as described is not to bev limited by any of the specific examples which may have,

been given for the purpose of illustration, but only by the following claims. Having thus described my invention, I claim: 1. A lubricant comprising a mineral lubricating oil and 2%to 10% of para-cymene to lower the pour point of theoil.

.2. A lubricant consisting of a mineral lubricating oil and 2% to 10% of para-cymene to lower the pour point of the oil.

3. A lubricant comprising a lubricating oil containing paraflin wax and 2% to 10% of'para-cymene to lower the pour point of the oil.

4. A lubricant consisting of a lubricating oil containing paraflin wax and 2% to 10% of paracymene to lower the pour pointof the oil.

5.; A lubricant comprising a straight heavy gear lubricating oil, 1% to 10% of para-cymene, and 5% of an aluminum chloride condensation product of naphthalene and chlorinated parafiinwax to lower the pour point of the oil.

6. A lubricant comprising a bright stock lubrieating oil, 1% to 10% of para-cymene, and 5% of an aluminum chloride condensation product of naphthalene. and chlorinated parafiin wax to lower the pour point of the oil.

THOMAS J. BROWN. 

